This root vegetable is a hardy perennial but is normally grown as an annual. The black-skinned, white-fleshed roots grow longer than 20 cm and wide of about 4 cm across the neck. The plants grow to about 90 cm tall and produce yellow flowerheads. The whole plants are edible, even if they are grown for their roots that have an unusual flavor and are eaten cooked. The young leaves and shoots of overwintered plants and the young flower buds and their flower stalks are also delicious cooked.
Scorzonera has the same requirements as carrots. All they need is a fertile, deep and light soil for their roots to develop well and straight. It also has low nitrogen requirements so if grown as an annual it must be rotate.
Grow scorzonera from fresh seeds sow in situ in spring. Sow seeds about 1 cm deep in rows about 20 cm apart. When the seedlings are large enough they must be thin out to 10 cm apart. Water the plants over the dry spells. To be ready for harvest, the roots need at least 4 months to develop. Being a cool season crop, the roots may be left in the ground over the winter, making sure you cover the plants with a layer of straw or bracken to a depth of about 15 cm if you live in severe climates. You can also lift the roots and store them in boxes in cool conditions.
Start harvesting scorzonera in autumn and continue in spring, but if the roots are too thin just left them in the ground and harvest them next autumn. If you want to harvest young leaves and shoots, cover the plants with a layer of about 15 cm o straw or leaves in early spring. The young, blanched leaves will just grow through this layer. Harvest them when they are about 10 cm tall. For flower buds just leave some roots in the ground during winter with no protection and they will flower in the spring or early summer. Harvest the unopened buds with about 8 cm of stem.